Having searched the 'net high and low, there is no indication that an antenna is built-in or included.
Given the worse circumstance, a simple 12" rubber antenna, available at most auto shops, and big box stores, should do the job for less than $20.00.
I'm still buying it. I can hide a small am/fm antenna in a lot of places. Besides, I want to plug my ipod into this sucker and rock out to my itunes.
The ipod and USB ports are most likely in the back. A remote ipod connector can easily be obtained and drilled next to the front of the unit. They cost about $10.00 online.